Parasites are types of organisms that live inside or on a host organism, relying on the host to get its food and nutrients at the host's expense.

Sometimes parasites don't cause any harm to their hosts and they may not even notice them. However, some parasitic infections can grow and reproduce in human bodies, even impacting their organs until they begin feeling ill.

Though malaria and giardia are two of the most well-known parasites to impact humans, many other types exist as well.

Some parasites can cause infections in humans: - Protozoa - Single-celled organisms that can live inside human bodies and reproduce, sometimes causing serious infections like giardiasis which can be contracted by drinking water with the giardia protozoa. - Helminths - Multi-celled organisms that can live inside your body are different than protozoa as they can live outside the body, too. Helminths are most commonly referred to as 'worms' including flatworms, tapeworms, thorny-headed worms, and roundworms. - Ectoparasites - Multi-celled organisms that live on your skin including mosquitoes, fleas, ticks, mites, and other insects and arachnids.

Parasites can infect humans in numerous ways including through food, waste (fecal-oral route), water, soil, and blood (protozoa and helminths). Sexual contact can spread certain protozoa. Vectors like insects, but mainly arthropods, can spread other parasites.

It's important to note that most parasites don't cause any symptoms or disease in most humans.

Parasites are treated through different methods depending on the diagnosis. Most of the time, medications are prescribed but other methods are also effective at stopping infection. The majority of these medicines are antiparasitics, antibiotics, and pyrethroids. Creams and ointments are also used.

Medications are also used to treat symptoms of parasitic infections like diarrhea, body aches, and fever.

There is currently no evidence that epsom salt baths can help kill parasites and pull other metals out of the body. One unfounded theory suggests that magnesium and sulfate derived from salt water can draw out toxins from the body, but there is no data to suggest this occurs in humans nor that it is plausible biologically.

It is possible to use electricity to kill parasites in water, but this method has not been widely demonstrated with humans. In general, data suggests that certain electromagnetic frequencies can kill certain parasites, but is not a highly used or particularly data-backed method for use in humans.

Ultraviolet light at specific wavelengths can kill some parasites but not all, and has not been widely used in humans for this purpose. Germ-killing properties exist in UVC light—the smallest and most energetic ultraviolet light—but this light can also cause severe damage in humans. It is carcinogenic and can damage human cells, harm corneas, cause sunburns, increase the risk of skin cancer, and cause other very harmful impacts in human bodies, which is why it is not widely used.

Parasitic infections impact between 1 - 2 billion people per year throughout the world, but especially in tropical climates. Seeking professional medical care is the best method for treating parasites in human bodies.